1221133331 has 24 divisors (see below), whose sum is σ = 1368525312. Its totient is φ = 1088564400.

The previous prime is 1221133313. The next prime is 1221133351. The reversal of 1221133331 is 1333311221.

It is not a de Polignac number, because 1221133331 - 2¹⁸ = 1220871187 is a prime.

It is a super-2 number, since 2×1221133331² = 2982333224158311122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1221133351) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2637206 + ... + 2637668.

It is an arithmetic number, because the mean of its divisors is an integer number (57021888).

Almost surely, 2^1221133331 is an apocalyptic number.

1221133331 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1221133331 is a deficient number, since it is larger than the sum of its proper divisors (147391981).

1221133331 is a wasteful number, since it uses less digits than its factorization.

1221133331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 863 (or 852 counting only the distinct ones).

The product of its digits is 324, while the sum is 20.

The square root of 1221133331 is about 34944.7182132007. The cubic root of 1221133331 is about 1068.8605014799.

Adding to 1221133331 its reverse (1333311221), we get a palindrome (2554444552).

The spelling of 1221133331 in words is "one billion, two hundred twenty-one million, one hundred thirty-three thousand, three hundred thirty-one".